Railway-brake.



PATENTED JUNE 23, 1903.

` P. HALLOT.

RAILWAY BRAKE.

APPLIUATION FILED AUG. 2s. 1901.

3 SHEETS-SHEET 1.

H0 MODEL.V

No. 731,894. l PATBNTED JUNE 2s, 1903.

1 P. HALLOT.

lRAILWAY BRAKE.

APPLIoATIoN FILED 111111.23. 1901.

no MODEL. a snnnss11nm 2.

@wwf ifm? 1 No. 731,894. y PATBNTED JUNE 2a, 1903.

1 HALLOT. RAILWAY BRAKE.

APPLICATION FILED AUG. 23, 1901.`

l0 MODEL. 3 SHEETS-SHEET 3.

l A j M l mno, wAsumaroN, n. c.

tvo.731,894;`

PatentedJ une 23, 1903.

UNITED STATES'- PATENT nnrcn.

PAUL HALLOT, OF VINCENNES, FRANCE.

RAI LWAY-BRAKE.

SPECIFICATION ib'rming part of Letters Patent No.4 731,894-, dated J une23, 1903. V

Application filed August 23,1901. Serial No. 73,066. (No model.)

To all whom t may concern,.-

`Be it known that I, PAUL HALLo'r, engineer, a citizen of France, residing at 79 Rue de Fontenay, Vincennes, France, have invented certain new and useful Improvements in Railway-Brakes, of which the following is a specification.

This invention relates to certain improvements in railway-brakes designed to increase the rapidity of the responso to the controllinggear of all the brakes of a long train and to renderthe application of all the brakes simultaneous. These results are obtained by the use of a pressure-reducing accelerator, (fitted under each carriage,) combined with a special controlling cock or valve located on the enl gine.

` the improved `accelerator' The accelerators tried up to the present but very imperfectly fulfil the purpose required of them, as" they can only work with a somewhat considerable reduction of the pressure, and, indeed, they can only be brought into action in emergency stoppages. In any case they do not expedite the coming into action ofthetail-brakes .relatively to those of the head.

In the annexed drawings, Figure l shows in vertical section.

i i Fig. 2 is an elevation of the controlling cock itself rigid with the central or valve providedy with its `pressure gage or regulator. Fig. 3 is a vertical section thereof. Fig. 4 is a sectional view of the reducingvalve.

The accelerator consists of a metal vcasing or box formed in two `parts a and 6 which `are screwed together and provided with an elastic diaphragm c. The lower part a is interposed in the main conduit d. T he diaphragm c is perforated at its center to allow lof the passage of a hollow cylinder c, with which it is rigidly connected and which is spindle f, which On one end of the `is screwed into its base.

` central spindle f is fixed avalve g, by means of which` the acceleratorcommunicates with the atmosphere, and on the other end is a pistonlh, having a surface or area equal to that of the valve g.` Ona level with the openi p smaller base of the c one t.

i ing of the cylinder e is a valve-cone c', fitted `5 slidablyon the spindle f and normally pressed upwardy by a spring la, bearing against the This action is,

however, counteracted by the preponderating action of an adjusting-spring m, bearing on the o ne hand against the larger base of the cone c' and on the other hand against a Washer n, the position of which can be varied by means of the regulating-screw o. A third springp is arranged between the screw-plug q, which closes the part a, and a nut r serves to adjust its initial tension and therefore the sensitiveness of the valve g. The cylinder e is provided with numerous holes s, and the part of the accelerator situated above the piston 7L communicates with the atmosphere through an orifice t.

In reality the piston h does n ot intervene in the working of the apparatus, its object being to compensate for the eect of the pressure on the valve g, and thus render the action of this valve independent of the pressure existing in the main conduit. A further object of the interposition of the opposing spring k is to compensate for the various kinds of `modifications that the tension of the spring mwould undergo by reason of variations of temperature or from other causes.` These` causes producing effects of the same kind,

but ina contrary direction, on the two springs m and 7c would have no result which would insure the constancy of the regulation of the apparatus. Furthermore, the essential function of the spring la is to raise the cone t and keep it away from the cylinder e to a greater or less extent directly a fall of pressure in the main conduit CZ has caused the diaphragm c to descend a certain distance and has thus withdrawn the cone rl from the preponderating action of the spring m.

The apparatus is thus reduced to two groups of movable parts: First. The first group comprises the diaphragm c, the cylinder c, the spindlef, and the valve g, the Whole of this arrangement being kept raised and the valve closed by the action of the spring p, which is so adjusted that the valve only opens at a certain preponderance of the pressure above the diaphragm or by a certain fall of pressure in the main conduit d, which comes to the same thing, since the same pressure exists on both sides of the diaphragm. .'Second.

:The second group is formed by the movable; cone t', which is suspended between the two antagonistic springs fm and 7s, the first of which preponderates so long as the diaphragm c is raised, whereas it ceases to act directly ICO this diaphragm has fallen a certain amount. This action may be regulated to the required degree by means of the screw 0. Under these conditions When the engineman causes compressed air to enter the main conduit d the cone t will rise until equilibrium of pressure be established above and below the diaphragm c. When he will establish the necessary reduction of pressure under the diaphragm to cause the valve g to open, the whole of the parts of the first group will fall sharply, so compressing the spring p, and they will only rise again under the action of this spring when the equilibrium of pressure is restored in the two parts of the apparatus through the play which takes place between the cylinder e and the cone 1l, which latter is raised by the spring 7c. For the whole of the very brief period during which `the valve g remains open a certain fraction of the air from the main conduit d has escaped into the atm osphere,so that each accelerator transmits to the succeeding one a perfectly definite reduction of pressure greater to a known ex tent than that which it itself received.

It will be readily understood that by arranging a special manometer at the entry and the eXit of the apparatus the tension of the spring fm may be empirically regulated, and hence the movements of the valve t' in such a mannerthat the reductionl of pressure of which' is equal to 1.05 in the example chosen, so that by calling d the initial reduction of pressure, d the reduction received by the accelerator of the coach of row fn, We have: d:(l.05) 'n' d.

The minimum initial reduction of pressure d' is ot' necessity equal to that which is necessary to effect the working'of the valve of the first accelerator-say, for example, eighty grams. We shall have in this case the following series of successive reductions:

Theoretic propor- Appr o-Xim ate tions practlcal proportions.

Car No.1......'..... 80 grams 80 Car No. 10 124 grams 125 Car No. 20 202 grams 205 Car No. 30. 331 grams Car No. 40 536 grams 540 Car No. 50 .l ST3 grams 875 From which, if a reduction of pressure ot' eight hundred and seventy-live grams be necessary to work the brakes, it is obvious that the rst forty-nine brakes will not come into action before the iiftieth, since it is only the coming into action of the ftieth accelerator which will determine this reduction of pressure in the main conduit.

As a matter of fact it was hitherto quit-e different. To transmit with sufficient rapidity a reduction of pressure of eight hundred and seventy-five grams to the iiftieth coach, the engineman is in reality obliged to effect a more considerable reduction of pressure at the head, the effect of which is to bring about a much more rapid and energetic braking at t the head than at the tail of the train. This defect is very aggravated by the back pressure which is produced in the main conduit at the moment of the closing of the enginemans valve and the eifect of which is to take off the head-brakes.

By referring to the list above it Willbe seen that the initial reduction of pressure effected by the engineman must Vary with the number of coaches in the train.V

Figs. 2 and 3show the special arrangement of the valve or cockof the engineman which enables him to effect by an always identical operation such reduction of pressure as is necessary.- The controlling-lever wis normally vertical-that is to say, when the valve cuts off the different pipes or passages leading thereto-via, the main conduit d, which extends through an arc of ninety degrees; the pipe 0:, leading to the compressed-air reservoir at six kilograms; the passage y, Fig. 3, leading to the atmosphere; the passage a', leading to the pressure-reducing regulatorthe passage l in the plug 2-of the valve deviates forty-five degrees relatively to the lever w. Under these conditions'it will be seen IOC) that by slightly shifting the lever to the right of air through the outlets 9 and 10, leadingA to the atmosphere, the port l0 being adapted to be opened or closed to a greater or less extent by a threaded Valve 5, provided with a handle fixed for controlling the same. The handle 6 travels over two concentric graduation-circles, one indicating the number of coaches in the train, ten, twenty, thirty, and

the other the corresponding initial reduction of pressure. On starting the engineman puts the handle over the graduation corresponding to the number of coaches in the train, and he reads opposite the initial reduction of IIO IIS

i as `the reduction of is itself the smaller.

` and brings it back directly into the vertical position. ,A manometer indicates to him, on the one h and, the initial minimum reduction of pressure thusobtained and, on the other hand, the maximum reduction of pressure efiected after the complete application of all the brakes. Any engineman will in avery short time be able` to determine the right movement to be imparted to the lever w, ac `cording to the results in dicated by the manometer. It is obvious thatthe screw pointer 5 will close the passage 7 to an extent so much the greater as the number of coaches in the `train is the higher.

The advantages of this system are the following:

First. The accelerator does not obstruct the main conduit d and air passes freely therein,

which is not the case with apparatus of this, `kind which only work by the variable resistance offered tothe flow ofthe air. p

Second. The working of the apparatus is independent of the pressure existing in the i main conduit, and accidental leakage cannot bring it into action.`

Third. The accelerator acts with very slight reductions of pressure, and4 it allows an amount of air'to escape so much the slighter pressure, which it receives 1 Fourth. It always'increases whatever the "amount of reductionof pressure the rapidity `of thetransmission to the brakes of the last f coaches without emptying the main conduit,

which is notthe 'case with the known accell: erators,which withslight reductions not only 45 eighty the engineers valve.

\ ,"until the reduction of .3 Ion car two opens until the reduction jysurein the portion of the main pipe from the engine to car two becomes 88.2.

` do not come into action, but also interfere 4o ablereductions empty the conduit, thus occasioning waste of air, which retards the puttingoff of the brakes by f serve of air in the main reservoir.

pressure ot', say,

with the flow of air and which with considerdiminishing the re- An initial reduction of I grams is made by the engineer from erator of car one to open and to escape air pressure becomes Then it closes and accelerator of preseighty-fou 1.

til the reduction is 92.6, and so on.

. 1 The accelerator on the preceding. coach is not brought into action, because. the reduction of pressure that acts upon it is equal to difference ismaximum and equal to eighthundred and-seventy-ive twentieths equal 243.7grams. By reference to page 5,1ines'1 to 4,

and it will be noted that reach accelerator is This causes the accel` Then itV closes and accelerator on car three opens unplay by a reduction *ofl `the brakes results from this fact that each accelerator can only bring into action the following, the preceding ones resting immovable. The accelerator on car n escapes such a quantity of air that may reduce the pressure in the portion of the main from the engine to the accelerator on car (n+1) tothe desired degree. Accelerator on car fortyeight` escapes such a volume of air that the `reduction in the main as far as car forty-nine would become 789.8. At this instant no one of the brake-valves enters into action, as we assume their action can only be brought out Y by a reduction of eighty grams; but as soon as the accelerator on car forty-nine plays it determines in the whole main the reduction of eight hundred and seventy-five grams, and then simultaneously all the brakes enter into action.

I claim.

l. `A pressure-reducing accelerator consisting of a central spindle f screwed into the bottom ofthe perforated cylinder e which is connected to a perforated elastic diaphragm c said spindle carrying the exhaust-valve g which is kept on its seating by the spring p so long as the same pressure exists on both the faces of the diaphragm a cone-valve t'. slidably fitted on said spindle j' and situated between two springs 7c and m one or other of` which comes into action according to the position of the diaphragm c and the resulting action of which may be regulatedby a screw o for the purpose of varying` the duration of opening of the valve g and of obtaining an accelerator capable of increasing the reduction of pressure in a proper known ratio and adjustable at will, said accelerator coming into action with but a veryslight reduction of pressure also regulatable, so as to do away with theetfects of backpressure and the total exhausting of the main conduit and not offering any obstacle to the circulation. of the air in this conduit, substantially as described. 4 j

- 2. In a railway-brake, the combination with the pressure-reducing accelerators and the engineers Valve of a pressure-reducing regulator interposed between the engineers valve and the atmosphere for obtaininga determinate initial reduction of pressure in the main pipe, and means for controlling such IOO initial reduction of pressure to correspond j with the number of-cars in the train, `substantially as described.

In testimony whereof I have hereunto set my vhand in presence ot' two subscribing witnesses.

- PAUL I-IALLOT.` Witnesses:

EDWARD P. MACLEAN, A. FREY. 

